function output = ge_poly(X,Y,varargin)
% Reference page in help browser: 
% 
% <a href="matlab:web(fullfile(ge_root,'html','ge_poly.html'),'-helpbrowser')">link</a> to html documentation
% <a href="matlab:web(fullfile(ge_root,'html','license.html'),'-helpbrowser')">show license statement</a> 
%



AuthorizedOptions = authoptions( mfilename );

Y=Y(:);
X=X(:);


      altitude = 1.0;
  altitudeMode = 'clampToGround'; 
   description = '';
       extrude = 0;
    autoClose = true;      
            id = 'poly';
         idTag = 'id';
     lineColor = 'ffffffff';
     lineWidth = 1.0;
   msgToScreen = false;
          name = 'ge_poly';
     polyColor = 'ffffffff';
       snippet = ' ';
    tessellate = 0;
     timeStamp = ' ';
 timeSpanStart = ' ';
  timeSpanStop = ' ';
    visibility = 1;
innerBoundsStr = '';
       region = ' ';


 

parsepairs %script that parses Parameter/Value pairs.

if msgToScreen
    disp(['Running :',mfilename,'...'])
end

if ( isempty( Y ) || isempty(X) )
    error('empty coordinates passed to ge_poly(...).');
elseif length(Y) ~= length(X)
    error('Length of Y is different to length of X');
end

if ~(isequal(altitudeMode,'clampToGround')||...
   isequal(altitudeMode,'relativeToGround')||...
   isequal(altitudeMode,'absolute'))

    error(['Variable ',39,'altitudeMode',39, ' should be one of ' ,39,...
        'clampToGround',39,', ',10,39,'relativeToGround',39,...
        ', or ',39,'absolute',39,'.' ])
    
end   

if region == ' '
	region_chars = '';
else
	region_chars = [ region, 10 ];
end


id_chars = [ idTag '="' id '"' ];
poly_id_chars = [ idTag '="poly_' id '"' ];
name_chars = [ '<name>',10,name,10,'</name>',10 ];
description_chars = [ '<description>',10,'<![CDATA[' description ']]>',10,'</description>',10 ];
visibility_chars = [ '<visibility>',10,int2str(visibility),10,'</visibility>',10 ];
lineColor_chars = [ '<color>',10, lineColor([1,2,7,8,5,6,3,4]) ,10,'</color>',10 ];
polyColor_chars = [ '<color>',10, polyColor([1,2,7,8,5,6,3,4]),10,'</color>',10 ];
lineWidth_chars= [ '<width>',10, num2str(lineWidth, '%.2f'),10, '</width>',10 ];
altitudeMode_chars = [ '<altitudeMode>',10, altitudeMode ,10,'</altitudeMode>',10 ];
if snippet == ' '
    snippet_chars = '';
else
    snippet_chars = [ '<Snippet>' snippet '</Snippet>',10 ];    
end
extrude_chars = [ '<extrude>' int2str(extrude) '</extrude>',10 ];
tessellate_chars = [ '<tessellate>' int2str(tessellate) '</tessellate>',10 ];

if timeStamp == ' '
    timeStamp_chars = '';
else
    timeStamp_chars = [ '<TimeStamp><when>' timeStamp '</when></TimeStamp>\n' ];
end

if timeSpanStart == ' '
    timeSpan_chars = '';
else
    if timeSpanStop == ' ' 
        timeSpan_chars = [ '<TimeSpan><begin>',timeSpanStart,...
            '</begin></TimeSpan>',10 ];
    else
        timeSpan_chars = [ '<TimeSpan><begin>',timeSpanStart,...
            '</begin><end>' timeSpanStop '</end></TimeSpan>',10 ];    
    end
        
end

header = ['<Placemark ',id_chars,'>',10,...
            name_chars,...
            timeStamp_chars,...
            timeSpan_chars,...
            visibility_chars,...
            snippet_chars,...
            description_chars,...
            region_chars, ...
            '<Style>',10,...
                '<LineStyle>',10,...
                    lineColor_chars,...
                    lineWidth_chars,...
                '</LineStyle>',10,...
                '<PolyStyle>',10,...
                    polyColor_chars,...
                '</PolyStyle>',10,...
            '</Style>',10,...
          '<Polygon ',poly_id_chars,'>',10,...
              extrude_chars,...
              altitudeMode_chars,...
            '<outerBoundaryIs>',10,...
              extrude_chars,...
              '<LinearRing>',10,...
              extrude_chars,...
              tessellate_chars,...
              altitudeMode_chars,...
                '<coordinates>',10];
      
footer = ['</coordinates>',10,...
      '</LinearRing>',10,...
    '</outerBoundaryIs>',10,...
    innerBoundsStr,...
  '</Polygon>',10,...
'</Placemark>',10];


X=[NaN;X;NaN];
Y=[NaN;Y;NaN];

nanIX = isnan(X.*Y);
polyStartIx = 1+find(nanIX(1:end-1)&~nanIX(2:end));
polyEndIx = find(~nanIX(1:end-1)&nanIX(2:end));
%nPolygons = length(polyStartIx);
output = '';
for x = 1:length(polyStartIx)
    %generate Coords        
    coordinates = [];
    if (polyEndIx(x)-polyStartIx(x))>=2
        for ii = polyStartIx(x):polyEndIx(x)
            coordinates = [ coordinates, ...
                            sprintf('%.16g,%.16g,%.16g ', X(ii), Y(ii), altitude),10];
        end %for

        %close unclosed polygons if necessary
        if autoClose&&...
                (X(polyEndIx(x))~=X(polyStartIx(x))||Y(polyEndIx(x))~=Y(polyStartIx(x)))
            if msgToScreen
                disp('Closing unclosed polygon...')
            end
            coordinates = [ coordinates, ...
                          sprintf('%.16g,%.16g,%.16g ',...
                          X(polyStartIx(x)), Y(polyStartIx(x)), altitude),10];
            if msgToScreen
                disp('Closing unclosed polygon...Done')                      
            end
        end   % if
        output = [ output, header, coordinates, footer];    
    end %if
end

if msgToScreen
    disp(['Running ',mfilename,'...Done'])
end
